Does trading significantly impact the width and the heavy tails of the distribution? Following the observation that the frequency
displays jumps predominantly at the trading intervals every 15 minutes (see Figs. REF  and [1]}), we isolate
those time periods and compare histograms only consisting of data
around the trading intervals with the remaining distributions for all other intervals without trading. To this end we assume
that the trading takes place every full hour, at 15 minutes, 30 minutes
and 45 minutes after every full hour. Around those time stamps, we cut a window of 5 minutes
of the frequency recordings to be analyzed as the frequency at the
trading interval while the remaining data is left for comparison. See Fig. REF  for an illustration, using frequency recordings from RTE [2]}.
